#856811

CSS

:root {
  --muddy-brown: #856811;
  --muddy-brown-rgb: 133 104 17;
  --muddy-brown-oklch: oklch(0.532 0.103 88.1);
}

.element {
  color: var(--muddy-brown);
  background-color: hsl(45 77% 29%);
  border-color: oklch(0.532 0.103 88.1);
}

Tailwind CSS v4

@theme {
  --color-muddy-brown: #856811;
  --color-muddy-brown-50: #fff5d4;
  --color-muddy-brown-100: #f5e7c1;
  --color-muddy-brown-200: #e5d3a2;
  --color-muddy-brown-300: #ccb679;
  --color-muddy-brown-400: #b89b53;
  --color-muddy-brown-500: #a28125;
  --color-muddy-brown-600: #896e22;
  --color-muddy-brown-700: #6e581b;
  --color-muddy-brown-800: #523f11;
  --color-muddy-brown-900: #392c0b;
  --color-muddy-brown-950: #241901;
}

SCSS

$muddy-brown: #856811;
$muddy-brown-rgb: 133, 104, 17;
$muddy-brown-light: mix(#fff, $muddy-brown, 20%);
$muddy-brown-dark: mix(#000, $muddy-brown, 20%);

.element {
  color: $muddy-brown;
  box-shadow: 0 0 0 2px rgba($muddy-brown, 0.35);
}